Bioidentical Hormones - U.S. Senate Special Committee on Aging

55
The WHI results have led to revisions of clinical guidelines for hormone therapy use. The
U.S. Preventive Services Task Force, 6 American College of Obstetricians and Gynecologists, 7
American Heart Association, 8 Canadian Task Force on Preventive Health Care, 9 and the North
American Menopause Society'" now recommend against the use of estrogen with or without a
progestogen to prevent CHD and other chronic diseases. Hot flashes and night sweats that are
severe or frequent enough to disrupt sleep or quality of life are currently the only compelling
indications for hormone therapy. The WHI results suggest that key factors to consider in
deciding whether to initiate hormone therapy in a woman with these symptoms (assuming she
has a personal preference for such therapy) are where she is in the menopausal transition and
whether she is in good cardiovascular health. A younger, recently postmenopausal woman-one
whose final menstrual period was 5 or fewer years ago-at low baseline risk of CHD, stroke, or
blood clots is a reasonable candidate for hormone therapy. Conversely, an older woman many
years past menopause, who is at higher risk of these conditions, is not Use of hormone therapy is
best limited to 2 to 3 years and generally no more than 5 years, as breast cancer risk increases the
longer hormones, particularly estrogen plus progestin, are used.
The WHI trials will undoubtedly remain the "gold standard" of evidence on the health
effects of hormone therapy for years to come, but their limitations must be acknowledged.
Although the WH I provided clear data on the benefits and risks of hormone therapy in women
aged 60 and older and ended the increasingly common practice of starting hormones in these
women for the express purpose of preventing CHD, the overall findings likely overstate the risks
for healthy women aged 40 to 59 who begin hormone therapy closer to menopause onset.
Moreover, only one type and dose of oral estrogen and progestogen was tested, so the results
may not apply to other formulations, doses, and routes of administration. There are few or no
trials on alternative hormone medications, particularly custom-compounded "bioidentical"
hormones. The lack of data on these agents, however, should not be construed to mean that they
are safer or more effective at preventing chronic disease; more research is needed to answer
these questions. Until such data are available, the rnident trategy"-and one ed ..!1
major medical organizations in the U.S.-is to assume all formulations have a similar safety and
risk profile.
Follow-up studies that have been conducted to help clear up confusion after the WHI
The divergence between earlier observational studies, which suggested that hormone
therapy might protect against heart disease, and the WHI trials, which did not, raised concern
that the coronary benefit seen in observational studies might simply reflect the fact that women
who choose to use hormone therapy tend to be healthier, have greater access to medical care, and
embrace health-promoting habits (e.g., eating a nutritious diet and exercising regularly) more
readily than women who do not choose to use hormones. Nevertheless, the concordance between
observational studies and the WHI for other endpoints, particularly stroke, which have lifestyle
determinants similar to those for CHID, suggest that these biases are not the primary explanation
for the discrepant CHD results." .2 Instead, a closer examination of available data suggests that
the timing of initiation of hormone therapy in relation to menopause onset may affect the
association between such therapy and risk of CHD. Hormone users in observational studies
typically start therapy within 2-3 years after menopause onset, which occurs on average at age 51